If you're really so keen on natural selection, we should stop doing medicine altogether. I mean, why save all those weaklings who got cancer or those pushovers who can't handle being run over by cars? Well, how about because letting people die preventable deaths is kinda really fucking awful... But, hey, maybe when idiots like you die of covid-19 because you didn't take even the simplest precautions, natural selection will make humanity a bit smarter. You must be really looking forward to improving the gene pool! Isn't evolution fun?
Of course, I know what you really mean is "I can't be bothered to inconvienience myself even slightly even if I might be killing someone, so I'll come up with a half-baked philosophy to justify my selfish attitude"